Roughly two methods have recently been studied and developed as a means for increasing the electron beam drawing throughput. The first method is to form a pattern by reduction and projection of an electron beam using a stencil mask. This method can realize high throughput, but formation of a mask is difficult at high cost. The second method is to perform drawing at once simultaneously using a point beam and variable rectangular beam as a conventional electron beam drawing method.
A method using a plurality of electron optical systems by assigning one electron beam to one electron optical system comprised of an electron lens and deflector is defined as a multicolumn method. A method of causing one electron optical system to transmit a plurality of electron beams is defined as a multibeam method.
As a multibeam type charged-particle beam drawing method, an electron beam emitted by one electron source is split into a plurality of electron beams by an aperture array to perform drawing (Japanese Patent Laid-Open No. 9-245708). This method can correct the beam interval between electron beams to a designed position by using a multi-deflector array for the positional error of each electron beam caused by a plurality of lenses or deflectors.
According to this multibeam drawing method, the positions of a plurality of electron beams may not be adjusted to designed target values due to the manufacturing errors of the electron lens and projection optical system, oblique incidence of an electron beam to the optical axis, a change in electron beam over time, and the like. The multi-deflector array has many wiring lines and requires a high-precision, high-speed analog driving circuit. It is difficult to control the multi-deflector array at high speed.